1. Field of the Invention
The present invention relates generally to medical devices and methods for treating closed wounds and incisions and for managing moisture therein, and in particular to a system and method for draining and/or irrigating tissue separations, such as surgical incisions, and for compressing and stabilizing a dissected or traumatized field with ambient air pressure created by an external patient interface component and a vacuum source.
2. Description of the Related Art
Tissue separations can result from surgical procedures and other causes, such as traumatic and chronic wounds. Various medical procedures are employed to close tissue separations. An important consideration relates to securing separate tissue portions together in order to promote closure and healing. Incisions and wounds can be closed with sutures, staples and other medical closure devices. The “first intention” (primary intention healing) in surgery is to “close” the incision. For load-bearing tissues, such as bone, fascia, and muscle, this requires substantial material, be it suture material, staples, or plates and screws. For the wound to be “closed,” the epithelial layer must seal. To accomplish this, the “load bearing” areas of the cutaneous and subcutaneous layers (i.e., the deep dermal elastic layer and the superficial fascia or fibrous layers of the adipose tissue, respectively) must also at least be held in approximation long enough for collagen deposition to take place to unite the separated parts.
Other important considerations include controlling bleeding, reducing scarring, eliminating the potential of hematoma, seroma, and “dead-space” formation and managing pain. Dead space problems are more apt to occur in the subcutaneous closure. Relatively shallow incisions can normally be closed with surface-applied closure techniques, such as sutures, staples, glues and adhesive tape strips. However, deeper incisions may well require not only skin surface closure, but also time-consuming placement of multiple layers of sutures in the load-bearing planes.
Infection prevention is another important consideration. Localized treatments include various antibiotics and dressings, which control or prevent bacteria at the incision or wound site. Infections can also be treated and controlled systemically with suitable antibiotics and other pharmacologics.
Other tissue-separation treatment objectives include minimizing the traumatic and scarring effects of surgery and minimizing edema. Accordingly, various closure techniques, postoperative procedures and pharmacologics are used to reduce postoperative swelling, bleeding, seroma, infection and other undesirable, postoperative side effects. Because separated tissue considerations are so prevalent in the medical field, including most surgeries, effective, expedient, infection-free and aesthetic tissue closure is highly desirable from the standpoint of both patients and health-care practitioners. The system, interface and method of the present invention can thus be widely practiced and potentially provide widespread benefits to many patients.
Fluid control considerations are typically involved in treating tissue separations. For example, subcutaneous bleeding occurs at the fascia and muscle layers in surgical incisions. Accordingly, deep drain tubes are commonly installed for the purpose of draining such incisions. Autotransfusion has experienced increasing popularity in recent years as equipment and techniques for reinfusing patients' whole blood have advanced considerably. Such procedures have the advantage of reducing dependence on blood donations and their inherent risks. Serous fluids are also typically exuded from incision and wound sites and require drainage and disposal. Fresh incisions and wounds typically exude blood and other fluids at the patient's skin surface for several days during initial healing, particularly along the stitch and staple lines along which the separated tissue portions are closed.
Another area of fluid control relates to irrigation. Various irrigants are supplied to separated tissue areas for countering infection, anesthetizing, introducing growth factors and otherwise promoting healing. An effective fluid control system preferably accommodates both draining and irrigating functions sequentially or simultaneously.
Common orthopedic surgical procedures include total joint replacements (TJRs) of the hip, knee, elbow, shoulder, foot and other joints. The resulting tissue separations are often subjected to flexure and movement associated with the articulation of the replacement joints. Although the joints can be immobilized as a treatment option, atrophy and stiffness tend to set in and prolong the rehabilitation period. A better option is to restore joint functions as soon as possible. Thus, an important objective of orthopedic surgery relates to promptly restoring to patients the maximum use of their limbs with maximum ranges of movement.
Similar considerations arise in connection with various other medical procedures. For example, arthrotomy, reconstructive and cosmetic procedures, including flaps and scar revisions, also require tissue closures and are often subjected to movement and stretching. Other examples include incisions and wounds in areas of thick or unstable subcutaneous tissue, where splinting of skin and subcutaneous tissue might reduce dehiscence of deep sutures. The demands of mobilizing the extremity and the entire patient conflict with the restrictions of currently available methods of external compression and tissue stabilization. For example, various types of bandage wraps and compressive hosiery are commonly used for these purposes, but none provides the advantages and benefits of the present invention.
The aforementioned procedures, as well as a number of other applications discussed below, can benefit from a tissue-closure treatment system and method with a surface-applied patient interface for fluid control and external compression.
Postoperative fluid drainage can be accomplished with various combinations of tubes, sponges, and porous materials adapted for gathering and draining bodily fluids. The prior art includes technologies and methodologies for assisting drainage. For example, the Zamierowski U.S. Pat. Nos. 4,969,880; 5,100,396; 5,261,893; 5,527,293; and 6,071,267 disclose the use of pressure gradients, i.e., vacuum and positive pressure, to assist with fluid drainage from wounds, including surgical incision sites. Such pressure gradients can be established by applying porous sponge material either internally or externally to a wound, covering same with a permeable, semi-permeable, or impervious membrane, and connecting a suction vacuum source thereto. Fluid drawn from the patient is collected for disposal. Such fluid control methodologies have been shown to achieve significant improvements in patient healing. Another aspect of fluid management, postoperative and otherwise, relates to the application of fluids to wound sites for purposes of irrigation, infection control, pain control, growth factor application, etc. Wound drainage devices are also used to achieve fixation and immobility of the tissues, thus aiding healing and closure. This can be accomplished by both internal closed wound drainage and external, open-wound vacuum devices applied to the wound surface. Fixation of tissues in apposition can also be achieved by bolus tie-over dressings (Stent dressings), taping, strapping and (contact) casting.
Surgical wounds and incisions can benefit from tissue stabilization and fixation, which can facilitate cell migration and cell and collagen bonding. Such benefits from tissue stabilization and fixation can occur in connection with many procedures, including fixation of bone fractures and suturing for purposes of side-to-side skin layer fixation.
Moisture management is another critical aspect of surgical wound care involving blood and exudate in deep tissues and transudate at or near the skin surface. For example, a moist phase should first be provided at the epithelial layer for facilitating cell migration. A tissue-drying phase should next occur in order to facilitate developing the functional keratin layer. Moisture management can also effectively control bacteria, which can be extracted along with the discharged fluids. Residual bacteria can be significantly reduced by wound drying procedures. In some cases such two-stage moist-dry sequential treatments can provide satisfactory bacterial control and eliminate or reduce dependence on antibiotic and antiseptic agents.
Concurrently with such phases, an effective treatment protocol would maintain stabilization and fixation while preventing disruptive forces within the wound. The treatment protocol should also handle varying amounts of wound exudate, including the maximum quantities that typically exude during the first 48 hours after surgery. Closed drainage procedures commonly involve tubular drains placed within surgical incisions. Open drainage procedures can employ gauze dressings and other absorptive products for absorbing fluids. However, many previous fluid-handling procedures and products tended to require additional clean-up steps, expose patients and healthcare professionals to fluid contaminants and require regular dressing changes. Moreover, insufficient drainage could result in residual blood, exudate and transudate becoming isolated in the tissue planes in proximity to surgical incisions.
Still further, certain hemorrhages and other subdermal conditions can be treated with hemostats applying compression at the skin surface. Free fluid edema resorption can be expedited thereby.
Yet another area of wound-dressing and wound-healing technology is what is referred to as “moist wound healing.” Three major components that constitute the external and physical environment of the healing wound should, in an ideal wound-healing environment, be controlled. First, wound healing is inversely related to bacterial growth. Second, it has been shown that, holding other variables constant, there is a relationship between the moisture level at the wound-site and the rate of epithelial advancement. The final important characteristic is the surface contact property of the wound dressing. The surface contact property can help to control the other two major factors, but must be made of a suitable material that promotes endurance of the dressing as well as comfort to the patient.
As one example, a piece of thin foam is one format used as a dressing in moist-wound healing applications. The external face of the thin foam may have larger pore sizes for allowing enough moisture retention initially, but then allowing drying to occur with the dressing still in place. Because this foam does not adhere to the wound, it could be moved or removed without disrupting the epithelium. However, this practice has heretofore been limited to use with relatively small incisional wounds, as the thin foam is incapable of managing the amount of exudates from larger, fresh wounds, or being securely held against a raw wound over a larger surface area. Moreover, if exudates accumulate under the foam piece, the foam will lose surface contact which allows bacteria to build up, among other undesirable consequences.
In general, epithelium advances or migrates best if moisture is initially maximized to mature the epithelium (e.g., stratifies, thickens and forms keratin), after which moisture should be minimized. Although the idea of moist wound healing is now over 50 years old, the present invention applies moisture control concepts in systems and methods for closing various types of incisions.
Heretofore there has not been available an externally-applied patient interface including an air press and an incision-closing method with the advantages and features of the present invention.